LiFePO4 gives $21k Return

[Submariner]

I am curious for folks who did the drop in replacement path for a house LFP and use a DC to DC charger from the engine AGM - what your real world experience is of being able to charge the house battery quickly enough off the engine alternator and shorepower (that are wired to the AGM)

I get 30 amps of engine charging, but with the boat underway, it consumes power also, leaving me about 15 amps an hour surplus that goes to house battery charging. The 420 watts of solar I have runs from sunrise to sunset and provides us with about 80% of all the power we consume, daily.

On shorepower, I have a 60 amp battery charger dedicated to my LFP house bank.

The best I could ever do for LFP charging, on the dock with shorepower: 60 Amps battery charger and 30 amps from solar. My Li3 supports up to 150 amps of charging.

 

[Pandion]

I am curious for folks who did the drop in replacement path for a house LFP and use a DC to DC charger from the engine AGM - what your real world experience is of being able to charge the house battery quickly enough off the engine alternator and shorepower (that are wired to the AGM)

Our '21 R27OB has a Victron LiFePo4 330AH house battery, so not exactly "drop-in" but close enough for the discussion.

Our Victron Orion XS DC-DC charger will pass up to 50 amps from whatever source is connected to the AGM start battery once the start battery reaches the voltage threshold for the Orion XS to start charging the house battery. The start battery is usually at (or close to) 100%, so the pass-through current usually happens relatively quickly.

When the AGM charge source is only the Yamaha F300, the Orion XS will generally pass between 40-50 amps to the house battery.

On shore power, the house battery is charged directly by 120V Victron charger that outputs 50A. The AGM start battery is still charged by the factory 20A Kisae charger. Once the start battery is full, the Orion XS will pass that 20A on to the house battery. Between the two 120V chargers, we can put ~70 amps into the house on shore power.